Creatine kinase isoenzymes specificities: histidine 65 in human CK‐BB, a role in protein stability, not in catalysis

FEBS Letters

Collombel, Christian²  Steghens, Jean-Paul²  Bozon, Dominique³  Mourad-Terzian, Tamara²  Min, Kyung-Lyum¹ 

[1] Department of Microbiology, College of Natural Sciences and Research Center for Microbiology, Seoul National University, Seoul 151-742, South Korea;Laboratoire de Biochimie C, Hôpital Edouard Herriot, 5 place d'Arsonval, 69437 Lyon Cedex 03, France;Laboratoire de Biochimie pédiatrique, Hôpital Debrousse, 29 rue Sœur Bouvier, 69322 Lyon Cedex 05, France

关键词: Brain-type creatine kinase;    Expression;    Site-directed mutagenesis;    Protein stability;    CK;    creatine kinase;    CK-BB;    brain-type creatine kinase;    CK-BB(His)6;    C-terminal 6 histidine-tagged CK-BB;    BCK;    gene encoding CK-BB;    CP;    creatine phosphate;    CCr;    cyclocreatine;    CCrP;    cyclocreatine phosphate;    ArgK;    arginine kinase;   

DOI  :  10.1016/S0014-5793(00)01614-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Creatine kinases (CK) play a prominent role in cell energy distribution through an energy shuttle between mitochondria and other organelles. Human brain CK was cloned and overexpressed in COS-7 cells. We then deleted His-65 and/or Pro-66 situated near the center of a flexible loop as shown by X-ray crystallography on mitochondrial and cytosolic CK. The ΔH65 mutant had nearly the same affinity for its substrates as wild isoenzyme, but its stability was very low. Unlike ΔH65, ΔH65P66 had a eightfold decreased affinity for creatine phosphate and was unable to dephosphorylate cyclocreatine phosphate. Our results demonstrate that, despite an overall similar shape of the proteins, this loop accounts for some subtle differences in isoenzyme functions.

【 授权许可】

Unknown